Joseph s



y (NoModex.)

as. DUNCAN.

- ORE GONGBNTRATOR.

No. 254,123. Patented Feb. 28,1882. v 1715.1. l

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\-.D i e .H I N 0- "IJ l n; A "mw W mlm UNITED STATES PATENT OFFICE.

JOSEPH S. DUNCAN, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR OF A PART TO A. P. BRAYTON AND JOHN N. WELLS, OF SAME PLACE.

oREcoNcENTRAToR.

SPECIFICATION forming part of Letters Patent No. 254,123, dated February 28, 1882.

Application filed August 5, 188i. (No model.)

To all lwhom it may concer-n Be it known that I, JOSEPH S. DUNCAN, of the city and county of San Francisco, State ofA California, have invented new and useful Im.

provements in Ooneentrators; and I do hereby declare the following to be a. full, clear,

and exact description thereof. V

My invention relates to that class otmining machinery known as coucentratorsif and it consists in the employment of a pan to which a rotary motion is given and at the same time a shaking or oscillating motion, whereby an advantageous e'ect is produced upon the auriferous earth and sand which are deposited upon the pan over its outer edge. l

It further consists in the means for accomplishing this result, and in minor details of construction, all ot' which will hereinafter more fully appear.

Referring to the accompanying drawings, Figure 1 shows a vertical section of my device. Fig. 2 shows a perspective ofthe sa'me.

Let A represent the bed or base blocks or support, to the center of which is secured a vertical king-post, B. This post is hollow, as shown, and communicates at its bottom and top with the outside.

Around the post B is a sleeve, C, having a flange, o, on its top. On this iiange another sleeve, D', rests. This sleeve surrounds the post B, and has an inner flange, d, ttingoverthe top of the post and protecting it from dust, sand, &c. It has a wide extended lange,.a, to which is bolted the pan E. The sleeve D is therefore the hub of the pan E, which by this meansmay revolve upon the kin g-post.

The outer edge of the pan is provided with a channelb, in the bottom of whichan aperture, e, is made, which is closed by a valve operated by a rod, f, and crank and spindle g, as shown.

The center of the pan E is perforated, so that an open communication is had with the hollow king-post.

Upon the surface of the pan E, near its mid dle, are S-shaped flan ges F, extending to the central hole, as shown. They support a protecting-plate, G.

Upon the lower sleeve, C, is firmly secured 5o a'large gear-wheel, H, with which abevel-pinion, I, meshes. This pinion is upon ashaft, J, the end of which carries a driving-pulley, K. Power, when applied to this pulley, revolves the gear-wheel E. Attached to this gear-wheel H is a bracket, L, having secured to its ends a vertical sleeve, l', in which an' upright spindle or shaft, M, fits, said spindle having on its lower end a pinion, N.

Upon thebase-block A, rigidly secured thereto, is a large gear wheel or ring, O, with which 6o the pinion N engages as it travels around. The upper end of the shaft M has attached to it a plate or disk, P, in which a crank-pin, p, is set.

A crank, It, is journaled upon the pin at one end, and is pivoted to the bottom of the pan E at the other, The motion transmitted by this mechanism may be thus sett'orth: When power is applied to the pulley K the gear-wheel His revolved and carries with it the bracket L, with its shaft M and plate P, which, being connected 7o through the crank R with the pan E, carries the said pan around with it, thus giving to it a rotary motion; but it will be seen that the bracket L, in revolving, causes the pinion N upon the shaft M to travel upon the large gear- 7 5' ring O, and thus gives to said pinion and shaft a rotary motion about their own centers. This is transmitted to the plate P, which-is made to revolve with the shaft upon which it is, and thus operates the crank R, whereby a secondary motion is given to the pan. Itis momentarily stopped, drawn back, and thrown forward, all the time continuing its principal revolution about the central or king post. It has therefore a rotary and an oscillating or shaking motion. The effect of these combined motions I will now explain, as well as the operation of the device.

The auriferous earth or sand and water are covered upon the revolving pan E at its outer edge and fall into the channel b. The centrifu gal force has a tendency to throw the heavier or precious particles to the extreme outer edge,

while the oscillating motion of the pan settles them to the bottom. As the operation is contin ued and the material is constantly thrown up against the outer rim, the channel b becomes filled with the precious particles, while the sand lies on top and is filled up against the rim,

forming a downward grade to the center of the roo pan, and it can be easily carried Oft' tothe center and wasted through the king-post by the stream of water which is constantly poured over the edge upon the pan. A further advantage Of this rotating pan is that the time it takes for the water to pass from the outside to the center, where it is wasted through the hollow king-post, is increased, thus giving the particles time to settle from the water. If the pan were stationary, the water would tlow directly from the periphery to the center, and, having but a short distance to cover, would be likely to carry some of the precious particles with it and waste them; but by revolving the pan the water is forced to take a spiral course to the center, and thus cover greater space, giving the particles time to drop out. As a consequence of this an increase in the volume of water is felt more gradually, and there will be no rushing force to the center. By opening the valve Ot' the aperture e the precious metal may be drawn oi from the channel b. rlhe S- shaped anges F, near the center of the pan, break the force of the water, conduct. the water to the central aperture, and discharge it directly. Without them the Water would not pass otl easily. The protecting-plate G prevents splashing, the water passing under it, between it and the pan.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The concentrating-pan E, with its periph eral channel b, said pan being journaled upon a central post and given arotary motion thereon by means of the connecting-crank R, plate 1),shaft M, traveling bracket L, gear-wheel H, pinion I, shaft J, and pulley K, and given an oscillating or shaking motion at the same time by means of the crank R, revolvingcrankplate P, shaft M, pinion N, large gear-ring O, traveling bracket L, gear-wheel H, pinion I, shaft J, and pulley K, the whole constructed to act in combination, substantially as herein described.

2. The concentrating-pan E, with its peripheral channel b and central aperture, in combination with the hollow king-post B and mechanism, substantially as and for the purpose herein described, for imparting to said pan a rotary and vibratory movement.

3. The concentrating-pan E, with its peripheral channel b and central aperture, and having the S-shaped iiangesF,in combination with the hollow king-post B, substantially'as and for the uses and purpose herein described.

4. The concentrating-pan E, with its peripheral channel b and central aperture, and havingtheS-shaped ilangesFandprotecting-plate G, in combination with the hollow kingpost B, substantially as and for the uses and purposes herein described.

5. The concentrating-pan E, with its peripheral channel b, said channel having an aperture, e, covered by a valve operated by the rod fand crank g, and the mechanism, substantially as and for the purpose herein described, for imparting to said pan a rotary and vibratory movement.

In witness whereof I have hereunto set my hand.

JOSEPH S. DUNCAN.

Witnesses:

J. I'I. BLOOD, C. l). COLE. 

